1. Technical Field
The present disclosure relates to a printed circuit board (PCB).
2. Description of Related Art
With the increasing speeds of integrated circuits (ICs), signal integrity is becoming one of the most pressing problem areas. Many factors, such as the parameters of the electrical elements of the PCB and the layout of the PCB, can affect the signal integrity, or lead to instability of the system, possibly even causing the system to breakdown. Thus, preserving signal integrity has become a key point in the design of a PCB.
Referring to FIG. 4, a related-art circuit topology coupling a driving terminal to two signal receiving terminals is shown. A driving terminal 10 is coupled to two signal receiving terminals 20 and 30 through corresponding transmission lines. The two signal receiving terminals 20 and 30 are connected together in a daisy-chain configuration. In this circuit topology, the distance a signal travels from the driving terminal 10 to the signal receiving terminal 20 is greater than the distance the signal travels from the driving terminal 10 to the signal receiving terminals 30.
Referring to FIG. 5, a graph illustrating signal waveforms 22 and 33 respectively obtained at receiving terminals 20 and 30 using the circuit topology of FIG. 4 is shown. Signals arriving at the receiving terminal 30 reflect back and forth along the transmission line causing “ringing” at the receiving terminal 20.